1. Field of the Invention
The present invention relates to an article of clothing with effects of back pain exercise, which can be worn as underwear or outerwear for preventing or relieving back pain and which has functions of posture improvement and body shape correction.
2. Description of the Related Art
Many people suffer from back pain due to various causes. Back pain is generally treated with conservative management and lifestyle education for maintaining and increasing physical strength. However, the biggest problem with back pain is that it often recurs. Back pain may lead to various diseases, the most common of which is lumbago. Although lumbago patients show no abnormality in the results of X-ray examinations and other tests, they suffer from pain caused by load concentration and accumulation of fatigue at the lumbar region due to insufficient muscle strength, posture problems, etc. Lumbago is generally treated with exercise therapy. Although the pain can be relieved by bed rest, it is difficult for the patients to take bed rest in modern living and in the economic environment. Therefore, the patients often exacerbate their symptoms.
The weight of the upper half of the body is supported by the lumbar spine that is positioned substantially at the center of the body. The lumber spine supports the weight of the upper half of the body and also receives a ground reaction force at the same time. Therefore, stress concentration occurs at the lumbar spine. As body weight increases, load on the lumbar spine, of course, also increases. The lumbar spine inherently has physiological lordosis. However, if the lordosis is increased, the pelvis tilts forward and force applied to intervertebral disks serves as a shear force. As a result, a stress is applied to paravertebral muscles and ligaments, which often leads to back pain. Displacement of sacroiliac joints is also considered to be the cause of back pain. The pelvis is constituted of two ilia and a sacrum with the sacroiliac joints disposed therebetween. Different from diarthroses, the sacroiliac joints are called plane joints or synarthrodial joints and are disposed at the center of movement. If the pelvis including the sacroiliac joints is tilted, it becomes difficult to stand upright. Accordingly, the abdominal muscle group mainly serves to reduce the lordosis of the lumber spine by tilting the pelvis rearward. If the abdominal muscles are strong, a high abdominal pressure is generated and force applied to the lumbar spine and the paravertebral muscles can be distributed.
Back braces, such as back supporters and back bands, have been described in reports regarding corsets. Back braces are generally prescribed in orthopedic clinics, but are also used outside medical facilities by many athletes irrespective of whether or not they have a lumbar disease. The purposes of using them are: (1) to limit vertebral segment motion; (2) to reduce load on the spine by increasing intra-abdominal pressure; (3) to suppress trunk muscle activity; (4) to reduce trunk muscle fatigue; and (5) to obtain a heat insulation effect. In research studies carried out in 1997, the effects of back braces in the acute phase of lumbago were studied by surface electromyogram. As a result, it was found that back braces have an effect of reducing dorsi muscle activity and fatigue. However, it has also been found that long-term use of back braces may cause disuse of dorsi muscles and reduction in lumbar spine mobility, which may lead to chronic lumbago. Therefore, it is important to begin exercise therapy after the pain is relieved by using a back brace for a certain period. The above-mentioned purposes corresponding to the advantages of corsets can be reliably achieved by the corsets. In particular, it is commonly known that it is important to reduce load on the spine by increasing intra-abdominal pressure for preventing and relieving back pain.
To enhance the above-described advantages, Williams has proposed Williams exercises, which is the most common method of exercise therapy for back pain. Regular practice of Williams exercises leads to posture correction, recovery of joint function, increase in muscle strength, and improvements in muscular coordination and tolerance so that motion velocity can be increased. In other words, supporting characteristics and mobility of the muscles, ligaments, and intervertebral joint capsules around the lumbosacral spine are normalized and posture is corrected for curing back pain. Various kinds of back pain exercises have been suggested. One common principle of the various back pain exercises is to extend muscles, ligaments, joint capsules including synovium and fibrous membrane, etc., in the lumbar portion of the back and the legs and to increase the muscle strength of the trunk muscles. In particular, importance is generally placed on strengthening abdominal muscles for reducing lumbar lordosis and increasing abdominal pressure.
Japanese Unexamined Patent Application Publication No. 2006-89856 describes leggings having highly elastic parts in predetermined areas in the back, the predetermined areas corresponding to areas where the skin is highly stretched at the buttocks and back thighs when the thighs are raised. The highly elastic parts have a higher modulus of elasticity in the height direction than those of parts in areas other than the predetermined areas in the back and in areas corresponding to at least an abdomen and front thighs in the front.
Japanese Unexamined Patent Application Publication No. 2001-192903 describes a girdle made of elastic knitting fabric and capable of improving the stability of hip joints, creating a youthful body shape and posture, relieving back pain, and aiding in the prevention of falling for old people.
In addition, Japanese Unexamined Patent Application Publication No. 2002-345866 describes a waist belt for relieving back pain.
Very few people are patient enough to continue Williams exercises for back pain, and it is difficult to manage time and have a suitable environment for restarting the exercises. Accordingly, there has been a demand for an article of clothing capable of assisting and extending muscles in the lumbar portion of the back and back thighs and strengthening the muscles in the abdomen and front thighs during daily life on the basis of the principle of back pain exercise. To comply with such a demand, an article of clothing capable of assisting the muscles and skeleton construction has been developed. Accordingly, development of an article of clothing that provides effects of back pain exercise based on the principle of Williams exercises or the like in a daily life environment is demanded.